Lee, I don't believe just making a bigger rudder is the way to go. If the current rudder is not powerful enough, this is due to there being too much sail out. Try reducing sail a bit and balance (and speed) will improve.

Is that some sort of little reefer? Is someone who covers a furlong called a furler? How do I stop my mast turning?My fins keep bending when I pedal. How do I make them stiff?My auto drains on the hulls don't seem to work, should I close them when sailing?Enquiring minds need to know these things